SCHEDULE 6LAUNCHING APPLIANCES AND EMBARKATION LADDERS
Regulations 2(3), 5 and 6
PART IVINFLATED BOAT LAUNCHING APPLIANCES
General
Definitions
1.1 In this Part the expression “working load” means the sum of the masses of:
1.1.1 the inflated boat and its full equipment;
1.1.2 the blocks and falls;
1.1.3 a launching crew of 2 persons each of mass 75 kg.; and
1.1.4 a mass of 60 kg. or the mass of the engine together with its fuel tank and sufficient fuel for two hours operation, whichever is the greater.
1.2 In this Part the expression “inflated boat” means any inflated boat or rigid inflated boat other than a dedicated rescue boat.
Construction
General
2.1 Every inflated boat launching appliance shall be so constructed to be:
2.1.1 capable of recovering the inflated boat and bringing it on board the ship;
2.1.2 readily available and not stowed or used for any purpose other than the launching of the inflated boat whilst the ship is at sea; and
2.1.3 provided with a suitable means for manual operation.
2.2 Each launching appliance shall be so constructed that the minimum amount of routine maintenance is necessary. All parts requiring regular maintenance by the ship’s crew shall be readily accessible and easily maintained.
2.3 A launching appliance shall be dependent only on manual effort, gravity or stored mechanical power which, if the boat is part of the ship’s statutory live saving appliances, is independent of the ship’s power supplies when used to launch the inflated boat. The arrangement shall be such that the inflated boat can be lowered by gravity when loaded in accordance with paragraph 1.1.3 and 1.1.4 and with its full equipment.
Strength
3.1 Every launching appliance serving an inflated boat shall, together with its winch if fitted, falls, blocks and other associated lowering gear be of such strength that the inflated boat with its full equipment can be safely lowered into the water from the embarkation position with a complement of 2 persons, when the ship has a list of up to 20 degrees either way and a trim of up to 10 degrees.
Stresses
4.1 Structural members and all blocks, falls, padeyes, links, fastenings and all other fittings used in connection with a launching appliance shall be designed with not less than a minimum factor of safety on the basis of the maximum working load assigned and the ultimate strength of the material used for construction. A minimum factor of safety of 4.5 shall be applied to all structural members and a minimum factor of safety of 6 shall be applied to the falls, links and blocks.
Static load test
5.1 Every launching appliance and its attachments other than the winch brakes shall be capable of withstanding a static test load, in a direction simulating a 20° list and 10° trim of not less than 2.2 times the maximum working load.
Winches
6.1 Every such launching appliance shall be provided with a winch when the inflated boat is situated more than 4.5 metres above the lightest sea going waterline.
6.2 Winch brakes shall be of robust construction and afford complete control and limitation of speed in the operation of lowering. The hand brake shall be so arranged that it is normally in the “ON” position and returns to the “ON” position when the control handle is not being operated. The mass of the brake lever shall be sufficient to operate the brake effectively without additional pressure. The winch brakes of a launching appliance shall be of sufficient strength to withstand:
6.2.1 a static load test with a proof load of not less than 1.5 times the maximum working load; and
6.2.2 a dynamic test with a proof load of not less than 1.1 times the maximum working load at the maximum lowering speed.
6.3 The speed at which the inflated boat is lowered into the water shall be not less than that obtained from the formula:
where
S=speed of lowering in metres per second and
H=height in metres from davit head, at the outboard position, to the waterline at the lightest seagoing condition
In the case of a ship where “H” exceeds 30 metres the lowering speeds need not exceed 1 metre per second.
6.4 Notwithstanding the requirements of paragraph 6.3 the speed of lowering shall not exceed 1.3 metres per second.
6.5 The brake gear of the winch shall include means for automatically controlling the speed of lowering to within the limits specified in paragraphs 6.3 and 6.4. A ratchet gear shall be incorporated in the winch.
6.6 Hand gear handles shall not be rotated by moving parts of the winch when the inflated boat is being lowered or hoisted by power.
6.7 The launching mechanism shall be so arranged that it may be actuated by one person from a position on the ship’s deck. The launching arrangements shall be such that the winch operator on the ship’s deck is able to observe the boat at all times during the lowering.
Wire rope falls
7.1 Wire rope falls shall be of rotation-resistant and corrosion-resistant steel wire rope.
7.2 The breaking tensile load of each wire rope used for lowering shall be not less than six times the maximum load on the wire rope when lowering, hoisting or stowing.
7.3 Wire ropes shall be securely attached to the drum of the winch, and the end attachments of the wires and other parts from which the inflated boat is to be suspended shall be capable of withstanding a proof load of not less than 2.2 times the load on such attachments and other parts.
7.4 Where wire rope splices or ferrule-secured eye terminals are used they shall be capable of withstanding a proof test of not less than 2.2 times the load imposed on them in service.
7.5 The falls of the inflated boat launching appliance shall be at least long enough to reach the water with the ship at her lightest sea-going condition under unfavourable conditions of trim and listed to 20° either way.
Cordage rope falls
8.1 Cordage rope falls shall be of manila or some other suitable material and shall be durable, unkinkable, firm laid and pliable. They shall be able to pass freely under any conditions through a hole 10 millimetres larger than the nominal diameter of the rope. The breaking load of each rope used for lowering inflated boats shall be not less than 6 times the maximum load on the rope when lowering or hoisting. Winding reels or flaking boxes for the manila rope falls shall be provided.
8.2 Such falls shall be at least long enough to reach the water with the ship at her lightest sea- going condition and listed to 20° either way.
Bollards
9.1 Suitable bollards or other equally effective appliances for lowering any inflated boat shall be provided in all cases where cordage rope falls are used. Such bollards or other appliances shall be sited so as to ensure that the inflated boat served by them can be safely lowered, the fairleads or lead sheaves shall be fitted so as to ensure that it shall not be lifted during the process of turning out or swinging out.